The main objective of this proposed study concerns the investigation of the possible uses of gycoproteins and carbohydrates as recognizable carriers for the selective uptake of chemotherapeutic agents by tumor cells. This will involve a study of the binding ad transport, via pinocytosis, of agents across the plasma membrane of both normal and tumor cells. It is known that the liver can rapidly clear desialylated glycoproteins from the circulation and that cell surface receptors showing specificity for termial galactosyl residues are responsible for initiating this phenomenon. The receptors may be enzymatic in nature and the activities of certain glycosyltransferase and glycosidase enzymes, which are capable of interacting with terminal glycosyl residues of glycoproteins, will be assayed in both normal rat liver, hepatoma and leukemic cell fractions. Should a glycoprotein be observed to bind and be specifically sequestered by tumor cells and not by normal cells, a cytotoxic agent, having a similar terminal carbohydrate sequence, would be prepared and might be found to be selectively sequestered by tumor cells resulting in a desired therapeutic effect. Certain enzymes, alkylating agents and antibiotics have been suggested as agents to be coupled with glycopeptide or carbohydrate in hopes to elicit such an effect.